Conventionally, the stapler in which a substantially U-shaped staple is driven into plural pieces of papers or the like and then the lower end portion of the staple is bent so as to bind the papers or the like has taken an important role in office work and other operations.
Handling of the staples for use in the conventional stapler is largely divided into a type in which the staple assembly composed of a plurality of substantially U-shaped staples connected in succession is accommodated directly within a magazine for usage and a type in which the staple storage cassette accommodating the staple assembly is loaded on the cassette loading magazine of the stapler. The former is often used for a portable small size stapler and the latter is often used for a large size stapler for office work.
As methods for forwarding the staple assembly within the staple storage cassette to a staple punch-out side, there are method in which a feeder abutting the rear end portion of the staple assembly is pressed by a compression spring to push the staple assembly to the punch-out side and a method in which the feeder is pulled by a tension spring from the staple punch-out side to push the staple assembly to the punch-out side. As another method, a method in which the staple assembly is introduced to the punch-out side with magnetic force of a magnet provided on the front end portion of the staple storage cassette has been used.
FIG. 14 shows an example of the staple storage cassette for use in a conventional cassette type stapler for office use.
FIG. 14 is a plan view of a condition in which the cassette cover of the staple storage cassette for use in the cassette type stapler for office use is removed.
In the cassette type stapler which uses the staple storage cassette 130 as shown in FIG. 14, a pusher 133 abuts the rear end portion of a staple assembly 132 accommodated in a cassette body 131 of a staple storage cassette 130. The staple assembly 132 is pushed in a forward direction by a pressing force of a compression spring 136 inserted into and supported by a rod 135 supported by a rear portion wall 134 of the cassette body 131 through the pusher 133. Then, a staple 137 at the head of the staple assembly 132 pushed to the punch-out side is configured to be driven out downward passing through a blade guide hole 138 by a staple pushing blade (not shown) (see for example, Patent Document 1).
FIG. 15 is a longitudinal sectional view of the cassette type stapler for office use which uses the staple storage cassette shown in FIG. 14.
The cassette type stapler 140 for office use comprises a horizontal base 141 having an anvil block 142 for guiding the bending of the bottom end portions of a staple, a loading portion pivot shaft member 143 provided on the horizontal base 141, a cassette loading magazine 144 supported by the loading portion pivot shaft member 143, a handle portion pivot shaft member 145 provided on the cassette loading magazine 144 and a push-down handle portion 146 supported by the handle portion pivot shaft member 145. A magazine supporting spring 147 is provided between the horizontal base 141 and the cassette loading magazine 144 and a handle supporting spring 148 is provided between the cassette loading magazine 144 and the push-down handle portion 146.
The staple storage cassette (not shown) loaded with the staple assembly composed of a plurality of the staples connected in succession can be inserted detachably into the cassette loading magazine 144. A blade passage 149 is provided at an one end portion of the cassette loading magazine 144 and a staple pushing blade 150 which can descend through the blade passage 149 is coupled with the push-down handle portion 146 (see, for example, Patent Document 2).
Patent Document 1: Japanese Patent Laid-Open Publication No. H07-96475
Patent Document 2: Japanese Patent Laid-Open Publication No. 2002-337065